This Petition for Review from the March 20, 2002 Finding and Award of the Commissioner acting for the Sixth District was heard October 18, 2002 before a Compensation Review Board panel consisting of the Commission Chairman John A. Mastropietro and Commissioners Donald H. Doyle, Jr. and Howard H. Belkin.

OPINION

JOHN A. MASTROPIETRO, CHAIRMAN. The claimant appeals from the March 20, 2002 Finding and Award of the Commissioner acting for the Sixth District. In that Finding and Award the trial commissioner concluded that the claimant sustained a 70% permanent partial disability to the index finger as well as an 11% permanent partial disability to his third (middle) finger and a 6% permanent partial disability to his fourth finger. All of these fingers were on his right master hand. The trial commissioner denied the claimant’s claim for benefits due to the injury’s involvement with his right shoulder. The trier also denied the claimant’s request for permanent partial disability benefits to his right wrist and right elbow due to lateral epicondylitis.

The claimant filed this appeal. The pertinent facts in this matter are as follows. On March 11, 1998 while in the course of his employment the claimant caught the fingers on his right master hand in a grinding machine. As a result he suffered a partial amputation of his right index finger and injured his third (middle) and fourth fingers of his right hand. The trier also found that the claimant sustained an injury to his right wrist.

In proceedings before the trial commissioner the claimant also claimed that his right shoulder was injured as a result of catching his hand in the grinding machine. The trial commissioner denied the claimant’s claim for benefits related to his right shoulder and thus denied the claimant’s claim for permanent partial disability benefits for the loss of use of his upper right extremity.

The record from the proceedings below reflects that the claimant underwent four surgical procedures on his right hand. These surgeries were performed by Dr. Stanley J. Foster. Dr. Foster reported that the claimant suffered a 41% disability to his upper right extremity. At the request of the respondents, the claimant was evaluated by Dr. William H. Fisher and Dr. Richard A. Bernstein. In his report dated March 25, 1999, Dr. Fisher stated, “Even though over one year has passed since the injury, the situation is deteriorating and estimation of permanency today is unreasonable. I have read Dr. Foster’s estimation of permanency dated Oct. 9, 1998 and feel that was a thorough and very reasonable estimation at that time.” Claimant’s Exhibit A-3 January 9, 2002.

Thereafter, Dr. Donald Kelly performed a Commissioner’s examination. Dr. Kelly in his July 12, 2000 report opined that the claimant sustained a 70% loss of the right index finger. In his examination notes, Dr. Kelly states, “Movements of the shoulder, elbow, wrist and hand are all normal.” Additionally, in a letter dated April 29, 1999, Dr. Fisher referred to the disability ratings given in Dr. Foster’s letter of October 9, 1998. Dr. Fisher stated, “I do not think that the 62% assigned to the amputated right index finger would truly transpose into an upper extremity estimate.” Respondents’ Exhibit 1, January 9, 2002.

In his appeal the claimant argues that the trial commissioner’s conclusion that the claimant was not entitled to permanent partial disability benefits for the loss of use of his right upper extremity was an abuse of discretion. The claimant argues that it was error for the trial commissioner to select and rely on some parts of Dr. Foster’s opinion and not accept other parts of his opinion. Determining what evidence and/or what parts of the evidence are to be believed and credited is the essence of a trial commissioner’s function.

It is the quintessential function of the finder of fact to reject or accept evidence and to believe or disbelieve any expert testimony. State v. Blades, 225 Conn. 609, 629, 626 A.2d 273 (1993). The trier may accept or reject, in whole or in part, the testimony of an expert. Smith v. Smith, 183 Conn. 121, 123, 438 A.2d 842 (1981).

Tartaglino v. Department of Correction, 55 Conn. App. 190, 195 (1999). See also, Bourgeois v. Meadow Lawn Care, 4463 CRB-6-01-11 (November 18, 2002). “In determining whether there has been an abuse of discretion, the ultimate issue is whether the court could reasonably conclude as it did.” (Citation omitted; internal quotation marks omitted.) Simmons v. Simmons, 244 Conn. 158 (1998). We do not agree with the appellant’s contention that the trier abused his discretion in his performance of this duty. Factual findings and conclusions of the trial commissioner will not be disturbed unless without evidence, contrary to law or based on unreasonable or impermissible factual inferences. Fair v. People’s Savings Bank, 207 Conn. 535 (1988). No such basis exists in the trial commissioner’s finding.

We therefore affirm the Commissioner acting for the Sixth District’s March 20, 2002 Finding and Award.